Ski bindings

ABSTRACT

Ski bindings for gripping the heel and toe portion of a ski boot. The heel and toe bindings are separate units which release by a snap action in response to the application of a predetermined force through the heel or toe of the boot to the respective bindings. A snap action blade provides the force for resisting lifting movement of the heel of the boot and for resisting swinging movement of the toe of the boot relative to the ski. Both the release force and the degree of movement permitted by the respective bindings is adjustable.

United States Patent Wilkes SKI BINDINGS [72] Inventor: Donald F.Wilkes, Albuquerque, N. Mex.

[73] Assignee: Rolamlte Incorporated, San Francisco,

Calif.

[22] Filed: Jan. 16, 1970 [21] Appl.No.: 3,463

Related [1.8. Application Data [63] Continuation-impart of Ser. No.717,] 14, March 29,

1968, Pat. No. 3,543,595.

[52] US. Cl ..280/1 1.35 T [51 Int. A63c 9/00 [58] Field ofSearch..280/l1.35 T, 11.35C

[56] References Cited UNITED STATES PATENTS Berlenbach l 1.35 T v [451June 20, 1972 3,497,230 2/1970 Hashioka et al ..280/1 1.35 T 3,201,1408/1965 Marker ..280/1 1.35 T

Primary Examiner-Benjamin Hersh Assistant Examiner-Robert R. SongAnomey-Bums, Doane, Swecker and Mathis ABSTRACT Ski bindings forgripping the heel and toe portion of a ski boot. The heel and toebindings are separate units which release by a snap action in responseto the application of a vpredetermined force through the heel or toe ofthe boot to the respective bindings. A snap action blade provides theforce for resisting lifting movement of the heel of the boot and forresisting swinging movement of the toe of the boot relative to the ski.Both the release force and the degree of movement permitted by therespective bindings is adjustable.

34 Claim, 23 Drawing Figures PATENTED JUN 2 0 m2 SHEET 0 5 OF.

FIG. 9

FIG. IO

PATENTEUJUH 20 1972 sum 05. 0F

QQD

PATENTEDJHHZO 1972 SHEET 08 or PATENTEnJunzo me SHEET 11 [1F SKIBINDINGS CROSS REFERENCE TO RELATED APPLICATIONS This application is acontinuation-in-part of my copending application Ser. No. 717,114entitled Snap Action Apparatus," filed Mar. 29, 1968 now US. Pat. No.3,543,595, issued Dec. 1, 1970.

BACKGROUND OF THE INVENTION This invention relates to ski bindings, andmore particularly todevices for temporarily securing the heel and toe ofa ski boot on a ski.

A typical heel binding grips the heel of the boot in such a way that itallows lifting of the heel off the surface of the ski to a limitedextent without releasing, but when sufficient upward force is applied tothe binding, such as when the forward motion of the ski suddenly-stopsor is abruptly reduced, the binding releases the heel and the boot isfree to separate from the ski. This is the primary mode of release forthe heel. it is also desirable for the binding to release the heel whenthe force is applied laterally to the heel of the boot, such as bycatching the ski on a chair lift or under a partially buried root orlimb.

In releasing the heel of the bootby applying a force upwardly, there aretwo factors to be considered. First, the heel binding should allowlimited lifting movement of the heel without releasing the binding andsecond the force required to release should be adjustable. Incross-country skiing, for example, large heel lift without release isdesirable. Racers, on the other hand, want the bindings to allow verylittle heel lift.

Bindings also should release at a force that corresponds to theparticular skiing conditions that are encountered. A low release forceis desirable for beginning and novice skiers, while a high release forceis required for slolam and downhill skiers. The heel binding, therefore,must be adjustable to accommodate the particular requirements of heellift and release force under a wide range of skiing ability andconditions.

Prior heel bindings typically do not allow independent adjustment ofheel lift and release force. For example, it is common to use a tensionspring for resisting heel lift and a toggle certing to the skier. Acommon disadvantage of conventional bindings is the lack of sensitivityof adjustment and the inability to release at the same force for a givensetting.

A desirable feature of ski bindings is that the bindings can be easilyclamped to the boot. The skier should be able to secure his boot in thebindings by inserting the toe of his boot into the toe binding and byplacing the heel on the ski and applying his weight to the heel into thebinding and have the heel binding positively grip the heel. This step-infeature should operate regardless of whether snow has packed under theheel of the boot and the presence of snow under the heel should notaffect adversely the accuracy of the release force or the amount of liftthat is pennitted before release.

Another desirable feature of ski bindings is that they be easilyreleasable manually by the skier when he wishes to remove the skies.Also, in the event of a fall, the skier should be able to release thebindings easily, even if he is in a position where it is difficult toreach the bindings. The bindings also should be capable of beingadjusted to the proper release force and relative release motion withoutdisassembling the binding, so that adjustments can be made while theskier is on the slopeto correct for terrain or snow conditions that heis about to encounter.

Conventional bindings often are difficult to fasten to the boot and toget out of in the event of an accident. For example, some bindingsrequire the skier to swing a lever by hand against the heel of the boot,while overcoming the force of the release spring, which maybe impossiblewhen the skier is not on firm ground. Similarly, release may require theskier to apply the preset release force to overcome the spring. Sucharlinkage for release when a preset displacement of the heel occurs.Usually, only adjustment of the spring tension is possible, and when thetension of the spring is changed, there is a corresponding change in thedegree of lift permitted. As a result, different heel bindings are useddepending upon the skill of the skier and the skiing conditions that areto be encountered.

A typical binding for the'toe of the boot provides lateral release toeither side of the ski. The toe binding is primarily intended to preventtorsional leg fractures, and twisted and sprained ankles and knees. Acertain amount of lateral movement may be desirable, according to theskill of the skier and the ski conditions. The force at which the toebinding releases the toe of the boot should also be adjustable and thetoe binding should continually urge the toe of the boot to return to acentered position with respect to the ski. The front or toe bindingshould also be capable of releasing the toe of the boot directly upwardwhen sufficient force is applied. When the skier is riding on a chairlift, it is possible for the tip of the ski to be caught, so that thetail of theski is thrown against the back of the chair. Also, certaintypes of falls make it desirable for the front binding to releasedirectly upward.

Most prior toe bindings either do not provide for lateral release, orutilize spring loaded cam actions that are ineffective when the toe isonly slightly offset from the center of the ski. Also, many priorbindings are unable to provide for a wide range of lateral movement ofthe toe.

In addition to the ability to adjust the heel and toe bindings forvarious conditions, another important feature that is desirable is theuniformity with which a binding releases. The binding should repeatedlyrelease at substantially the same force at a given force setting on thebinding. If the binding releases over a wide range of forces for thesame setting, then there is a danger that the binding will release witheither too little or too great a force and the uncertainty may bedisconrangements may prevent the skier from removing his skies readilyafter a fall.

SUMMARY OF THE INVENTION Accordingly, it is an object of this inventionto provide improved heel and toe ski bindings. I

A further object of this invention is to provide ski bindings in whichthe release force is accurately and conveniently adjustable. r

A still further object of this invention is to provide ski bindings inwhich the extent of motion of the heel and toe of the boot prior torelease is adjustableindependently of the release force adjustment.

Another object of this invention is to provide ski bindings which allowthe boot to be readily fastened in the bindings and released manually bythe skier. I

It is also an object 'of this invention to provide ski bindings in whichthe release force and deflection prior to release are adjustable over awide range.

These objects are accomplished in accordance with preferred embodimentsof the invention by heel and toe bindings which incorporate a conicalsnapper for yieldably urging the heel of the boot toward the ski surfaceand urging the toe of the boot toward the center of the ski. The conicalsnapper includes a thin, resiliently flexible blade. The inner end ofthe blade is mounted in such a way that it is stressed to assume atransversely curvedconfiguration, with the transverse curvatureprogressively decreasing toward the outer end of the blade. The blade isbistable and the blade is mounted in the binding so that in one stableposition the outer end of the blade bears against the base plate of thebinding when the boot is fastened on the ski. This arrangement causesthe blade to buckle progressively from the outer end toward the innerend as an increasing force is applied to the blade, until the bladesnaps over to the other stable position.

A lever connects the boot with the blade to press the outer end of theblade against the base plate as the boot applies a force to the bindingin the direction of release. In the heel unit, the lifting force appliedby the boot is applied directly to the lever, while in the toe binding,a transfer linkage is used to transmit lateral displacement of the toeof the boot to the vertically movable lever that is connected with theblade. As the force of the blade increases, the outer end of the bladeprogressively deflects until the blade ultimately snaps over to theopposite stable position. Both the front and the rear bindings providefor adjustment of the release force by changing the pivot point of thelever. The displacement permitted by the binding before release isadjustable by preloading the blade to cause the outer end of the bladeto be deflected when the heel isagainst the ski, or for the frontbinding when the toe is centered. Both the front and the rear bindingscontinually and uniformly urge the heel and toe toward their respectiveinitial positions until the force applied through the lever system tothe blade exceeds maximum resisting force provided by the blade. Whenthis occurs, the blade snaps over and the heel or toe of the boot isreleased.

DESCRIPTION OF THE DRAWINGS These preferred embodiments are illustratedin the accompanying drawings in which:

FIG. 1 is a perspective view of the ski bindings of this invention assecured on a ski and showing a boot fastened therein;

FIG. 2 is a perspective view of the heel unit of this invention;

FIG. 3 is a perspective view of the toe unit of this invention;

FIG. 4 is a side elevational view of the heel unit;

FIG. 5 is a longitudinal cross sectional view of the heel unit;

FIG. 6 is an exploded view showing the components of the heel unit;

FIG. 7 is a cross sectional view of the heel unit along the line 7-7 inFIG. 5;

FIG. 8 is a side elevational view of the heel unit with the coverremoved;

FIG. 9 is a front elevational view of the heel unit;

FIG. 10 is a cross sectional view of the heel unit along the line l0-l0in FIG. 5;

FIG. 11 is a cross sectional view of the heel unit along the line 1 11 Iin FIG. 5;

FIG. I2 is a longitudinal cross sectional view of the heel unit showingthe unit in its released position;

FIG. 13 is a rear elevational view, partially in cross section, of thetoe unit;

FIG. 14 is a cross sectional view of the toe unit along the line 14-14in FIG. 13;

FIG. 15 is a detail cross sectional view of the toe unit along the lineI5--15 in FIG. 13;

FIG. 16 is an exploded view of the components in the toe unit;

FIG. 17 is a top plan view, partially in cross section, of the toe unit;

FIG. 18 is a cross sectional view of the toe unit along the line 18-48in FIG. 13;

FIG. 19 is a longitudinal cross sectional view of a modified form of theheel unit;

FIG. 20 is a top plan view, partially in cross section of the modifiedheel unit;

FIG. 21 is a longitudinal cross sectional view of the modified heel unitshowing the unit in its released position;

FIG. 22 is a cross sectional view of the modified heel unit along theline 22-22 in FIG. 20; and

FIG. 23 is a cross sectional view of the modified heel unit along theline 23-23 in FIG. 20.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS In FIG. 1, a heel bindingunit 2 and a toe binding unit 4 in accordance with this invention areshown as mounted on a conventional ski 6. The units 2 and 4 engage theheel and toe of a ski boot 8 to hold the boot on the upper surface ofthe ski 6, while allowing limited movement of the heel and toe relativeto the ski. The heel unit 2 is shown in greater detail in FIG. 2, whilethe toe unit is illustrated in FIG. 3.

HEEL UNIT The heel unit 2 includes a base plate 10 which is secured tothe upper surface of the ski 6 by a pair of screws 12, as shown in FIGS.7 and 11. A stop bracket 14 is superimposed on the base plate 10 andsecured to the plate by welding or other suitable means. The bracket 14has a pair of slots 16 which are aligned with corresponding slots in thebase plate 10. The screws 12 extend through the bracket slots 16 andthrough the slots in the base plate 10 to hold the base plate firmlyagainst the surface of the ski 6. The base plate 10 also has a key slot18. A screw 20 extends through the slot 18 and is secured in the ski 6.The screw 20 has an enlarged shank portion between the screw threads andthe head which allows the plate to slide freely along the length of theslot 18. The slots 16 and 18 permit the base plate 10 to be adjustedlongitudinally of the ski to accommodate boots of different lengths, orto allow accurate positioning of the binding along the length of ski 6.

At the forward end, the base plate 10 has a raised platform 22 andridges 24 for supporting the heel of the ski boot 8, as shown in FIGS. 2and 9. The inclined sides of the ridges 24 are coated with a materialhaving a low coefficient of friction, such as polytetrafluorethylene.The peaks of the ridges 24 tend to bite into snow that may be caked onthe bottom of the boot heel, and since the snow or ice on the heel isnot frictionally supported by the inclined sides of the ridges, theridges form effective wedges which easily break off accumulations ofsnow or ice from the heel. Furthermore, the snow or ice cannot pack inthe bottom of the ridges because of the presence of the low frictionmaterial. Thus, the ridges in the platform effectively remove snow orice from the bottom of the boot heel and allow the heel to rest firmlyon the ridges 24 and the platform 22.

The stop bracket 14 includes an upwardly inclined portion 26 and thefront surface of the portion 26 serves as a stop for positioning theheel of the boot 8 when it is placed on the ridges and the platform 22,as shown in FIG. 5. The boot stop 26 has an internal guide slot 28 withan upwardly inclined leg portion and a horizontal leg portion adjacentthe base plate 10. A rod 30 extends through the slot 28 and is movablealong the slot. A step lever 32 has a tubular portion adjacent one endand the rod 30 extends through the tubular portion for hingedly mountingthe step lever 32 on the boot stop 26. The lever 32 extends forwardlyfrom the boot stop 26 and the outer end of the lever extends under theplatform 22 as shown in FIGS. 2 and 5. The outer end of the lever restson the surface of the ski 6.

As shown in FIGS. 5 and 7, a yoke 34 is pivotally mounted on oppositeends of the rod 30 for swinging movement relative to the base 10 andrelative to the step lever 32. The yoke 34 has a sleeve 36 formed alongthe upper edge through which a shaft 38 extends. The shaft 38 supports ahousing 40. The housing 40 includes a top wall 42, a front wall 44 andopposite sidewalls 46. Each sidewall 46 has an arcuate slot 48 throughwhich the shaft 38 extends (FIGS. 7 and 8). A perpendicularizing spring49 is positioned over the sleeve 36 and has fingers 51 which bearagainst the rear side of the yoke 34. The ends of the spring 49 haveblocks 53 through which the shaft 38 extends. The lower end of eachblock 53 bears against the lower side of the slot 48 to maintain theyoke in a radial position, as it is adjusted along the slot 48. Eachsidewall 46 also has an arcuate step 50 which is aligned with the slot48 so that the upper edge of the slot 48 is offset outwardly from thelower edge of the slot, as shown in FIG. 7. The upper edge of the slothas gear teeth 52 which mesh with the splines 54 at each outer end ofthe shaft 38. The lower edge of the slot 48 forms a bearing surface forsupporting the shaft and the blocks 53.

The position of the shaft 38 along the slots 48 is controlled byrotation of the shaft. As the shaft rotates, the splines 54progressively engage the gear teeth 52 and displace the shaft along theslot. Rotation of the shaft 38 is accomplished by a worm and geararrangement. A gear 56 (FIG. 7) is formed on the shaft 38 and a worm 58drives the gear 56. The worm 58 is mounted in driving relation with thegear 56 by a saddle 60 which is suspended from the shaft 38 on oppositesides of the gear 56 and passes around the worm to hold the worm inengagement with the gear 56. The saddle 60 is preferably formed ofresilient sheet metal and a portion of the saddle is resiliently biasedinto engagement with the worm. This saddle portion resists accidentalrotation of the worm 58 caused, for example, by vibration of the skiiswhile being transported.

The worm shaft includes a cylindrical portion of reduced diameter and aslotted head 62. The cylindrical portion is received in a socket 64(FIG. 6) formed in the front wall 44 of the housing. A retainer 65(FIGS. 6 and 9) has a socket at one end which cooperates with the socket64 for engaging the cylindrical portion on the worm shaft. The retainer65 is preferably formed of wear resistant metal since it bears the axialthrust of the worm shaft. The portion of the front wall adjacent thesocket 64 is inclined rearwardly to conform to the average slope of theworm 58 (FIG. 5). Since the shaft 38 moves along an arcuate path, thesocket for the worm shaft allows slight pivoting movement of the wormabout the socket. The helix angle of the worm 58 is such that the shaft38 is friction locked in position along the slot 48 by the worm, but itsposition can be changed by rotation of the worm.

A reactor 66 extends across the rear of the housing 40 (FIGS. 5 and Thereactor 66 has a pair of arms 68 which project forwardly along the outersurface of the sidewalls 46. The ends of the arms 68 have lateralprojections 70 which are received in holes 72 in the sidewalls 46. Thereactor 66 is provided with an arcuate groove 74 forreceiving the inneredge 76 of a thin, resilient, snapper blade 78; The blade 78 is shown inits unstressed condition in FIG. 6. The inner edge 76 has a radius ofcurvature that is greater than the radius of curvature of the bottom ofthe groove 74. The blade 78 also has a pair of tab portions 80 whichproject forwardly at opposite ends of the curved edge 76. The lateraledges 82 of-the blade 78 converge progressively toward the outer end 84of the blade.

A tension bar 86 is positioned on the forward side of the reactor 66. Apair of screws 88 extend through threaded holes in the tension bar 86and are received in sockets 90 on the forward side of the reactor 66.The tabs 80 of the blade are received in slots 92 at the opposite endsof the tension bar 86. During assembly, the blade 78 is aligned with thegroove 74, so that the edge 76 bears against the bottom of the groove.The tabs are then secured in slots 92 by-braising, welding or othersuitable means. Tension isthen applied to the tabs 80 by means of thescrews 88 to draw the lateral edges of the blade rearwardly, therebyimposing compressive stresses in the blade along the arcuate edge 76 andtensile stresses along the tabs 80 to cause the blade to assume atransverse curvature and to be stable at either of two positions onopposite sides of a neutral plane.

The blade 78 has a front face which corresponds to the upper surface ofthe blade and a rear face which faces toward the upper surface of theski 6. When the unit is in position for actively holding the heel of aboot on the surface of the platform 22 and on the corrugations 24, theblade 78 is in the bistable position in which the front face of theblade has a convex, substantially frustoconical shape. The tabs 80 causethe tension bar 86 to pivot about the ends of the screws 88 and tobecome substantially aligned with the lateral edges 82 of the blade, asshown in FIG. 8.

The outer end of the blade 78 bears against a lateral ridge 94 on thebase plate 10. The blade has a longitudinal slot 96 (FIG. 10) and aretaining screw 98 extends through the slot and is received in athreaded socket in the base 10 to prevent the outer end of the bladefrom being displaced away from the ridge 94 when the blade is snappedover to the'release position. The slot 96 allows the blade to movelongitudinally relative to the retaining screw 98.

The shape of the blade and the manner in which the blade is stressedcauses the blade to assume a transverse curvature and in which thecurvature of successive transverse cross sections of the blade decreasesfrom the inner edge 76 progressively toward the outer edge 84. As aresult, the blade buckles progressively from the outer end 84 toward thecurved edge 76 as a force applied to the reactor 66 is transmittedthrough the blade 78 to the ridge 94. The resistance to deflection ofthe outer end of the blade 84 by such a force progressively increases asthe outer end of the blade deflects, until the blade ultimately snapsover to the other bistable position. A more complete explanation of thisphenomenon is contained in my copending application Ser. No. 717,114,entitl'edfSnap Action Apparatus," filed Mar. 29, 1968, now US. Pat. No.3,543,595,issued Dec. 1, 1970.

If the blade 78 were naturally flat it would require the same force forsnapping over in either direction from one bistable position to theother. A large force for resisting deflection of the outer end of theblade, however, is desirable when the front face of the blade is in aconvex configuration for actively holding the heel of a boot on theplatform, but when the front face of the blade is concave and the unitis released, the force of the blade resists cocking the unit. Therefore,the blade 78 preferably has a slight preformed transverse curvaturewhich gives the front face a convex curvature independently of thecompressive and tensile stresses imposed by the reactor and tension barassembly. As a result of the preformed curvature in the blade, a greaterforce is required to snap the blade 78 from a holding position with thefront face convex than is required to snap the blade from a releasedposition with the front face of the blade concave.

Referring to FIG. 5, the position of the reactor 66 relative to the top42 of the housing is controlled by an adjusting screw 100. The screwextends through a slot 102 in the top 42, as shown in FIGS. 5, 8 and 10.The reactor 66 has a threaded hole 104 for receiving the screw 100. Theshank of the screw, as shown in FIG. 5, has a shoulder 106 which bearsagainst the lower surface of the top 42. The head of the screw has slots108 for turning the screw. The slots 108 preferably have the proper sizeand spacing to receive the edge of a coin, which serves as a driver forturning the screw 100. The head of the screw 100 also has a conicalsocket 109 for receiving and supporting the tip of a ski pole. When theskier inserts his ski pole in the socket 109 and presses downwardly, theblade 78 snaps over and the heel of the boot is released.

The shoulder under the head has a plurality of flats 110 and a springclip 112 (FIG. 8) is inserted between the top 42 and the head of thescrew. The clip 112 has a pair of cantilever arms 114 which engage theflats 110. Tabs 1 16 on the clip 1 12 are secured along the sides of theslot 102 and resist rotation of the clip relative to the top 42, so thatthe clip temporarily holds the screw in its adjusted position. The sidesof the tabs 116 serve as bearing surfaces for the screw 100. The centralslot in the clip allows the screw to move along the housing slot 102 asthe reactor position is being adjusted by turning the screw. The arms114 remain in engagement with the flats 110 to resist turning of thescrew 100, regardless of the position of the screw along the slot 102.

A prop 118 is used to facilitate snap over of the blade when the bladeis in the released position. This action is referred to as cocking theunit. The prop 118 is mounted for swinging movement on a pair ofbrackets 120 projecting from the lower side'of the tension bar 86. Ahinge spring 122 urges the prop 118 to swing counterclockwise as viewedin FIG. 12. Rotation of the prop 118, however, isrestricted by a pair ofcams 124 which engage the cam surface 126 on the reactor 66. The cams124 cause the prop 118 to swing rearwardly to the position shown in FIG.12, when the blade 78 has snapped over to the release position. When theunit is cocked so that the blade 78 is in the opposite stable position,the cams 124 engage the surface 126 on the reactor 66 (FIG. 6) and holdthe prop in its raised position. The lower end of the prop 118 is in theshape of a cog 128 in order to engage one of a series of transversegrooves 130 in the bracket 14.

A spring 132 is connected between the bracket 14 and the blade 78, asshown in FIG. 12, to displace the blade 78 forwardly when the bladesnaps over to the release position until the retaining screw 98engagesthe outer end of the slot 96. The hinge spring 122 swings theprop 118 downwardly when the blade snaps over and the spring 132 insuresthat the housing is sufficiently forward to permit the spring loadedprop 1 18 to support the tension bar 86 when the skier presses the heelof his boot downwardly on the lever 32.

The front wall 44 of the housing also includes a pair of flanges 134.The front face of each flange 134 has transverse serrations (FIG 6), anda heel clamp 136 is secured to the serrated faces of the flanges 134 byscrews 135. The heel clamp 136 has slotted openings 137 to permitvertical adjustment of the heel clamp 136 relative to the housing 40 toaccommodate boot heels of various heights. The clamp 136 has atransverse shoulder 138 for engaging a plate 139 on the upper edge ofthe boot heel, as shown schematically in FIG. 5. The heel clamp 136 alsoincludes a pair of cam surfaces 140 (FIG. 9) which are in position to beengaged by the boot heel plate 139 to resist lateral movement of theheel.

The housing 40 is enclosed by a cover 141. The cover includes oppositesidewalls 142. The cover 141 is mounted on brackets 143 projectingoutwardly from the sidewalls 46 of the housing and is secured to thehousing by screws 144. The sidewalls are provided with arcuate slots 145which are aligned with the ends of the shaft 38, as shown in FIG. 7. Anappropriate scale 146 is marked along the slot 145 to indicate the forcerequired for release of the unit. The cover has an opening 148 (FIG. 2)through which the head of the screw 100 extends. The opening 148 allowsaccess to the screw 100 for adjusting preload on the blade 78. The coverdoes not extend across the front of the housing 40 and the head 62 ofthe worm shaft for adjusting the leverage is accessible.

OPERATION OF THE HEEL UNIT In order to cock the unit from the releaseposition as shown in FIG. 12, the heel of the boot is applied againstthe lever 32 with the edge of the heel resting against the boot stop 26.As the skier applies his weight to the boot heel, the bar 30 which isconnected with the lever 32 moves downwardly along the inclined portionof the slot 28. The motion of the bar 30 is transmitted through the yoke34 and through the shaft 38 to the housing 40, thereby exerting adownward force on the housing. Movement of the housing is resisted bythe prop 118 which engages one of the grooves 130. The reaction forcetransmitted through the prop 118 is applied to the tension bar 86,thereby causing the housing 40 to rotate about the screws 88 whichconnect the tension bar 86 with the reactor 66. The relative motionbetween the reactor 66 and the tension bar 86 ultimately causes theblade 78 to snap over to its opposite stable position.

The linkages are designed such that the bar 30 is in the horizontal legof the slot 28 when snapover occurs. When the blade snaps over, theprojection 126 on the reactor 66 immediately swings the prop 118 out ofthe grooves 130 and the housing moves suddenly to the position shown inFIG. 5. The bias of the blade 78 urges the clamp 136 toward the surfaceof the ski 6 and the shoulder 138 in the clamp engages the plate 139projecting rearwardly from the heel of the boot 8.

If the heel of the boot attempts to lift from the platform 22, the forceof the heel is transmitted through the clamp 136 to the housing 40. Thehousing 40 is prevented from moving upwardly by the shaft 38 which isheld in position by the yoke 34. The housing, however, can accommodateupward movement at the heel by rotating clockwise, as viewed in FIG. 5,around the shaft 38. This motion of the housing 40 is transmittedthrough the top 42 of the housing to the reactor 66. Downward movementof the reactor 66, however, is resisted by the blade 78, which at itsouter end bears against the transverse ridge 94 on the base plate. Asthe force exerted upwardly by the heel 8 increases, the blade 78deflects at the outer end by progressively buckling along the transversecross sections from the outer end toward the inner edge 76 that issupported on the reactor 66. The deflection at the outer end of theblade 78 allows limited upward movement of the heel clamp 136 withoutcausing the blade 78 to snap over.

However, when suflicient force is applied through the heel to the heelclamp 139, the blade 78 snaps over to the opposite stable configuration.The snapping of the blade 78 causes the reactor 66 to rotate clockwise,as viewed in FIG. 5, about the ends of the screws 88 projectingrearwardly from the tension bar 86. The motion of the reactor 66 istransmitted to the housing 40 through the arms 68, thereby causing thehousing to rotate clockwise to the position shown in FIG. 12. At thesame time, the prop 118 swings downwardly into position for engaging thetransverse grooves and the housing remains in the position shown in FIG.12. The snap action of the blade 78 occurs suddenly and the motion ofthe housing immediately moves the heel clamp 136 away from the heel ofthe boot so that the boot is free to separate from the ski.

The heel unit also releases when sufficient force is applied laterally.The cam surfaces 140 on the clamp 136 are engaged by the heel plate 139and when a lateral force is applied, there is a component of forcetending to rotate the housing 40 about the shaft 38. When the lateralforce is sufficiently large, the blade 78 snaps over, releasing theheel.

If the skier finds that the upward force required for release is eithergreater or less than desired, he can change the force setting merely byturning the screw 62 to move the shaft 38 along the slot 48. In FIG. 5,the shaft 38 is shown near the lefthand end of the slot 48, so that arelatively large force is required for release. As the shaft 38 is movedtoward the right, the length of the lever arm between the shaft 38 andthe heel clamp 136 is increased, so that progressively smaller forcesare required for release.

The amount of displacement of the heel off of the platform 22 beforerelease occurs can be adjusted by means of the screw 100. By turning thescrew, the reactor 66 can be moved upwardly or downwardly relative tothe tension bar 86. This displacement of the reactor 66 causesdeflection of the outer end 84 of the blade, so that the additionaldisplacement required at the heel clamp 136 for snapover of the blade 78is correspondingly smaller. This adjustment can easily be made byinserting a coin or other spacer between the heel of the boot and theplatform 22 and then tightening the screw 100 until the blade 78 snapsover. The spacer is then removed.

As shown in FIG. 6, the head of the screw 100 has a conical counterboreto serve as a socket in which the end of a ski pole can be inserted torelease the unit easily. This manner of release requires considerablyless force than that required at the heel clamp 136 because the leverarm is correspondingly longer. The size and shape of the blade 78determines the range of forces that can be supported by the blade in itsconical configuration. By adjusting the tension exerted by the tensionbar 86, the degree of coning of the blade can be varied. This adjustmentis accomplished by turning the screws 88. Usually this adjustment wouldbe made by the manufacturer and the skier would adjust the force anddeflection characteristics by means of the screws 62 and 100,respectively.

TOE UNIT The toe binding unit 4 is shown in FIGS. 3 and 13 to 17. Theunit includes a swivel plate which is raised from the surface of the ski6 and has flanges 152 along the margins of the plate 150. The swivelplate 150 is secured to the ski 6 by a bracket 154, which is held inplace on the surface of the ski 6 by screws 156. The bracket 154includes a threaded center post 158 which is threaded into a sleeve 160.The sleeve 160 is enclosed within a hollow screw 162 having externalthreads. The screw 162 is threaded into a ring 164. A cap 166 is securedon the upper end of the screw 162 to prevent axial movement of thesleeve 160, while allowing rotation of the sleeve relative to the screw162. The cap 166 has a hexagonal opening 168 to receive an Allen wrenchfor rotating the screw 162 relative to the ring 164.

A spring biased detent 170 is clamped between the bracket 154 and thesurface of the ski 6. The detent 170 has a spherical projection 172which is received with a corresponding socket 174 in the swivel plate150 when the plate is aligned with the longitudinal axis of the ski.When torque is applied tending to rotate the plate 150 about the sleeve160, the sides of the socket 174 acts as a cam forcing the projectionout of the socket, so that the spring 170 no longer resists swingingmovement of the base plate 150.

A yoke plate 176 is secured to the ring 164 by welding. The plate 176has an integrally formed bearing portion 178 in which a rod 180 isinserted. A yoke 182 is mounted at the opposite ends of the rod 180 forswinging movement relative to the yoke plate 176. The upper end of theyoke 182 is formed with a sleeve 184 for supporting a transverse shaft186. The yoke 182 is substantially identical to the yoke 34 shown inFIG. 6.

The shaft 186 extends through arcuate slots 188 in the oppositesidewalls 190 of the housing 192. The arcuate slots 188 are providedwith gear teeth 193 along their respective upper edges, as shown in FIG.14, and the outer ends of the shaft 186 are splined to mesh with thegear teeth in the slots. Displacement of the shaft along the slot isaccomplished by a wonn and gear arrangement corresponding to the worm 58and gear 56 of the heel unit, as shown in FIGS. and 7. The gear 194 isshown in FIG. 13. The wonn 196 has a recessed portion under the headwhich is received in a slot 198 in the front wall 200 of the housing192. As shown in FIG. 15, a retainer 201 similar to the retainer 65 inthe heel unit cooperates with the slot 198 for supporting the worm forrotation. A saddle 199 holds the worm 196 in engagement with the gear194. The housing also has a top 202.

A thin blade 204 of resilient material has an inner edge that engages anarcuate notch 206 in a reactor 208. The inner edge of the blade 204 hasa larger radius of curvature than the bottom of the notch 206 and tabsextend rearwardly from the arcuate edge of the blade and are secured ina transverse tension bar 210. The bar210 is spaced for pivotal movementrelative to the reactor 208 by a pair of screws 212. The blade 204 andthe mounting arrangement for the blade in the reactor 208' i and tensionbar 210 and their associated components are substantially identical tothe corresponding components of the heel unit, as previously described.The outer end of the blade 204 rests against a lateral ridge 214 on theswivel plate 105. A retaining screw 216 extends through a longitudinalslot 220 in the blade and restricts lateral movement of the outer end ofthe blade while allowing longitudinal movement along the slot 220.

The reactor 208 has a pair of arms 222 extending rearwardly. Each armhas a projection 224 which is received in a hole 226 in the wall 190 toallow swinging movement of the reactor relative to the housing 192. Thepreload on the blade 204 is applied by a screw 228 which extends throughthe reactor 208. The screw has a shoulder 230 which bears against thelower surface of the top 202 and by turning the screw, the position ofthe reactor 208 relative to the top 202 can be adjusted in the samemanner as the reactor 66 of the heel unit. A spring clip 232 under thehead of the screw engages flats formed under the screw head to resistrotation of the screw. The screw 228 is received in a slot 234 in thetop 202.

At the rear of the housing 192, there are a pair of rearwardlyprojecting flanges 236 and 238. A toe clamp 240 is mounted between theflanges for limited rotational movement about a hinge pin 242. A toeguide 244 below the clamp 240 is pivotally mounted on the transverse bar180. The guide has rearward projections 246 which bear against the lowersurface of the toe clamp 240. An inclined cam surface 248 is provided onthe lower edge of the projections 246 for engaging an abutment 250 inthe toe of the boot 8. As shown in FIG. 14, the boot 8 has slots 252which receive the projections 246. The plate 150 has a raised platform254 which is spaced rearwardly from the projections 246, so that theedge of the boot 8 overhangs the platform 254 and can be wedged againstthe cam surface 248.

In order to allow the base to swing freely over the surface of the ski6, a friction reducing block 256 is positioned between the platform 254and the surface of the ski. The block 256, as shown in FIG. 14, iscovered with a layer 257 of low friction material such aspolytetrafluorethlyene.

The housing 192 is enclosed by a cover 258 which is mounted on a pair oflateral tabs 260 which project outwardly from the sides 190 of thehousing 192. The cover 258 has an access opening for the reactoradjustment screw 228 and an opening 264 to allow access to the leverageadjustment worm 196. The housing top 202 also has an opening 266 throughwhich an Allen wrench can be inserted in the socket 168 to adjust theheight of the plate 176 relative to the housing 150.

OPERATION OF THE TOE UNIT In order to clamp the boot toe inthe toebinding unit, it is necessary to cock the unit so that it is in theposition shown in FIG. 14..1his can easily be done by pressing down onthe toe clamp 240. The toe of the boot 8 is inserted while the heel ofthe boot is raised. The boot is moved forwardly until the front edge ofthe boot engages the toe clamp 240. The heel of the boot is then moveddownwardly to rest on the heel support surface of the heel binding unit.This movement causes the surface 250 of the grooves 252 in the toe ofthe boot to engage the cam surfaces 248 on the toe guide 244 and to liftup the front unit slightly, thereby introducing a slight deflection atthe outer end of the blade 204. i

When a lateral force is applied to the toe of the boot, this force istransmitted through the side of the groove 252 which bears against theprojection 246. When sufficient lateral force is applied to release thedetent 170, the housing and base plate swing together as a unit relativeto the bracket 154. As the toe clamp 240 continues to move laterallytoward the right, as viewed in FIG. 16, for example, the clamp 240swings clockwise-about the pin 242 to maintain its engagement with thetoe of the boot on opposite sides of the projections 246. Gradually, asthe surface 250 of the left-hand groove 252 and theleft-hand projection246 swings toward the central axis of the ski, the surface exerts aforce forwardly on the cam surface 248. Since the toe surface 250 isinclined, there is an upward component of force acting on the toe guide244, and this motion is transmitted through the toe clamp 240 to thehousing 192. When sufficient force has been applied through the surface248, the blade 204 snaps over and immediately releases the toe of theboot. The toe binding also releases, if an upward force is appliedthrough the toe of the boot to the guide 240, such asoccurs when the tipof the ski is caught on a chair lift or exposed root, or some otherobstruction. The force and the deflection required for release isadjusted in the same manner as the rear binding by means of the screws196 and 228, respectively. The front binding is also adjustable forboots of various thickness. By inserting a wrench into the socket 168and turning the barrel 164 relative to the plate 176, the position ofthe cam surface 248 relative to the platform 250 can be adjusted.

The action of both the front unit and the rear unit in snapping from anoperative to a release position permits the units to be easily enclosedto keep out snow. A boot of thin flexible material may be fastened alongthe edge of the base plate 10 of the heel unit and around the cover 141.Accordian pleats in the boot would allow relative movementbetween thecover 141 and the plate 10. Similarly, a boot may be fastened around theedge of the swivel plate 150 and around the cover 258. Since the outerend of the blade in both units does not move appreciably relative to thebase plate, other than to deflect, the boot may fit closely over theblade, resulting in a neat unitary appearance of the bindings.

MODIFIED HEEL UNIT A modified form of the heel unit of this invention isillustrated in FIGS. 19 to 23. The modified heel unit has substantiallythe same structure as the heel unit illustrated in FIGS. 2 to 12, exceptfor the arrangement for stressing the blade and for snapping the bladeover from a released position to a clamping position. Parts of the heelunit which are substantially the same as is illustrated in FIGS. 2 to 12are identified with the same reference numeral followed by a primesymbol.

A tension bar 268 is pivotally mounted on the sidewalls 46 of thehousing by a pair of arms 270 having projections which are received inholes 72' in the sidewalls 46'. The tension bar 268 supports a reactor272 by means of a pair of opposed grooves 274 at opposite ends of thetension bar 268. The grooves 274 have opposed parallel flat surfaceswhich engage corresponding surfaces on projections 276 at opposite endsof the reactor 272. The grooves and projections cooperate to resistpivoting movement of the reactor relative to the tension bar 268. A pairof screws 278 extend through threaded holes in the tension bar 268 andengage the forward edge of the reactor 272.

The blade 78 has a curved arcuate edge 76' and a pair of tab portions80' which project forwardly at opposite ends of the arcuate edge 76. Thetab portions 80' extend through slots 280 at opposite ends of thetension bar 268. As shown in FIGS. 20 and 23, the ends of the tabs 80'are bent over the forward edge of the tension bar 268 and welded at thetop surface of the tension bar. The reactor 272 has an arcuate groove282 in which the edge 76' of the blade is received. As shown in FIG. 20,the length of the reactor groove 282 is substantially less than thelength of the arcuate edge 76 to provide a transition zone for the bladebetween the connection of the tabs 80 with the tension bar 268 and theedge 76' with the reactor 272. The shape of the reactor 272 allows thecenter portion where the groove 282 is located to deflect forwardly asthe blade snaps over from one stable position to the other. Theadjustment screw 100 extends through a threaded slot 284 in the reactor272 for adjusting the position of the reactor and the tension barrelative to the top of the housing 42.

To assist in snapping over the blade 78 from a released position to aclamping position, a pivoted prop 286 is provided. The prop 286 has apair of tabs 288. A U-shaped bracket 290 is supported on the blade 278and the legs of the bracket 290 are pivotally connected with the tabs288 by a pin 292. The bracket 290 has a central slot 294 with opposedprojections 296 for engaging the blade 78 at a point spaced from thearcuate groove 282 in the reactor 272. The arcuate edge of the blade 78is gripped at the ends of the slot 294, as shown in FIG. 23. By mountingthe bracket 290 in this way, the bracket swings from the position shownin FIG. 19 to the position shown in FIG. 21 when the blade snaps over tothe released position. The stop bracket 14 has a plurality of V-shapedgrooves 298 which are in position for engagement by the lower end of theprop 286. A spring 300 extends between the end of the bracket 14 and theblade 78' for urging the blade forwardly in the slot 96' (FIG. 20).Another spring 302 is connected between the blade 78 and the prop 286for urging the prop to swing downwardly to the position shown in FIG.21.

The operation of the modified heel unit, as shown in FIGS. 19 to 23, issubstantially the same as that of the heel unit shown in FIGS. 2 to 12.As an upward force is applied to the housing by a ski boot, the top 42'and sidewalls 46 swing downwardly imposing additional forces on theblade 78 and causing the end of the blade to deflect against thetransverse ridge 94' on the base. When the blade 78 is no longer able tosupport the force exerted by the ski boot, the blade snaps over to theposition shown in FIG. 19 which frees the prop 286 to be pulleddownwardly by the spring 302 into engagement with the transverse grooves298. In order to clamp the binding on a ski boot again, the heel of theboot is pressed downwardly against the step lever. The prop 286 resistsdownward movement of the reactor 272, thereby causing the blade to snapover to the position shown in FIG. 19. As soon as the blade snaps, thebracket 290 swings to the position shown in FIG. 19 and the prop ispulled against the bottom of the reactor 272 and into the position shownin FIG. 19. The adjustment of the deflection of the outer end of theblade 78' is accomplished by turning the screw 100'. This changes theorientation of the reactor 272 relative to the housing, since thetension bar 268 is pivotally mounted by means of the arms 270 on thesidewalls 46 of the housing. When the blade snaps to release position,however, the prop 286 is in position to engage one of the grooves 298,regardless of the adjusted position of the reactor 272 at the time thatthe blade snaps.

Although the modified structure of the reactor 272 and the tension bar268 have been described with respect to the heel unit, this structuremay also be substituted for the corresponding structure in the toe unit.Of course, the toe unit does not include the prop 286 and so the propand associated structure is not necessary in the toe unit.

The toe and heel binding units of this invention have many advantagesover prior ski bindings. The release action uses the elastic behavior ofa progressively buckling transversely arched, normally flat sheetmaterial to provide a uniform and repeatable release characteristic. Therelease mechanism is substantially free of friction and is not adverselyaffected by accumulations of ice and snow in the binding. The force anddisplacement desired for release can be adjusted precisely withoutdisassembling the binding and without requiring any special tools. Themechanism permits the binding to be set by placing a spacer under theheel and then adjusting the displacement screw until the bindingreleases. The spacer is then removed. The toe unit is set by turning theboot to the desired release angle and then adjusting the displacementscrew until release occurs.

Both the toe unit and heel unit provide positive clamping of the boot tothe ski. The blade continually exerts a restoring force on the booturging it to return to its original position. The toe and heel unitspromote safety since they release both to the side and upwardly. 7

While this invention has been illustrated and described in severalpreferred embodiments, it is recognized that variations and changes maybe made therein without departing from the invention, as set forth inthe claims.

What is claimed is:

l. A ski binding comprising:

a base,

clamping means on said base, said clamping means including a transversepivot shaft mounted on said base and including lever means extendinglongitudinally of said base and pivotally supported on said shaft,

spring means extending between said lever means and said base, saidclamping means including a boot clamping abutment, said abutment beingon the opposite side of said transverse shaft from said spring means,said spring means yieldably resisting pivoting of said lever means aboutsaid shaft in a direction which moves said clampin abutment away fromsaid base, and release means mounted between said spring means and saidlever means for removing the resistance of said spring means in responseto pivoting of said lever means about said shaft when said abutmentmeans has moved a predetermined distance away from said base, saidrelease means allowing said lever means to pivot about said shaft tomove said abutment away from said base a distance greater than saidpredetermined distance without interference by said spring means,whereby release of said ski boot occurs substantially instantaneouslyand without sudden variations in spring resistance prior to release.

2. The ski binding according to claim 1 including a second transverseshaft on said base, link means extending between said second shaft andsaid pivot shaft, and means for displacing said second shaft relative tosaid base upon movement of said abutment beyond said predetermineddistance, whereby said clamping abutment moves away from said base uponrelease.

3. The ski binding according to claim 1 wherein said lever meansincludes means for adjusting the distance separating said clampingabutment and said spring means from said shaft, whereby the spring forcetransmitted by said spring means to clamping abutment is adjustable.

4. A ski binding comprising: a base, clamping means on said base, saidclamping means being movable a predetermined distance relative to saidbase from a position for clamping a ski boot on said base to a positionwherein a ski boot would be released in response to a predeterminedforce applied to said clamping means in a predetermined direction, saidclamping means including a clamping abutment and lever means movablewith said abutment about a transverse axis relative to said base, springmeans yieldably resisting displacement of said clamping means, saidspring means providing progressively increasing resistance in responseto displacement of said clamping means in said direction until saidpredetermined force causes said clamping means to move to said releasedposition, said spring means including a blade having an inner end and anouter end, said blade outer end being in engagement with said base, saidblade inner end being connected with said lever means for deflectingsaid blade upon pivoting said lever means about said axis, said springmeans having a greater resistance to deflection adjacent said inner endthan adjacent said outer end, and means for adjusting the magnitude ofsaid predetermined distance substantially independently of saidpredetermined force, whereby said blade deflects progressively fromadjacent said outer end toward said inner end.

5. The ski binding according to claim 4 wherein said clamping meansincludes a transverse shaft supporting said lever means for pivotingmovement about said shaft.

6. The ski binding according to claim 5 including a transverse bar,means mounting said bar on said base, and means connecting said shaftwith said bar for swinging movement of said shaft along a cylindricalpath about said bar, whereby swinging said shaft along said path changesthe leverage between said abutment and said blade, and said bar retainssaid lever means in a predetermined position with respect to said baseduring movement of said shaft along said path.

7. The ski binding according to claim 6 wherein said lever meansincludes a housing having a pair of side walls extending longitudinallyof said lever means, said side walls having arcuate slots therein, saidshaft extending through said slots, and means for temporarily lockingsaid shaft against movement along said slots.

8. A ski binding comprising a base, a housing, means connecting saidhousing with said base, said connecting means including means forpivoting said housing about a transverse axis relative to said base,means on said housing cooperating with said base for clamping a skiboot, reaction means, said reaction means including a blade of thinresiliently flexible sheet material interconnecting said housing andsaid base, said blade being stressed to seek to assume a substantiallyconical bistable configuration and being capable of snapping from aconcave configuration on one face of said blade to a concaveconfiguration on the opposite face of said blade upon a predetermineddeflection of said blade against said base, said transverse axis beingbetween said blade and said clamping means, said clamping means beingrendered inefi'ective upon snapping of said blade from one configurationto the other, whereby the application of a force against said clampingmeans is transmitted through said housing to said blade to deflect saidblade against said base progressively and ultimately to snap said bladewhen a predetermined force is applied to said clamping means.

9. A ski binding according to claim 8 wherein said blade has adjacentsaid housing a bearing edge located intermediate the lateral margins ofsaid blade and having legs extending outwardly therefrom at locations onopposite sides of said bearing edge, said reaction means also includingmeans for pressing against said bearing edge and for pulling on saidlegs to load said blade so that said sheet material thereof adjacentsaid bearing edge is in compression and the sheet material thereofspaced from said edge is in tension, whereby said blade is distortedelastically to seek alternately both of said concave configurations.

10. A ski binding according to claim 9 wherein said pressing and pullingmeans includes a reactor, said reactor having an arcuate groove therein,said bearing edge being arcuate and having a greater radius of curvaturethan said reactor groove, said bearing edge being received in saidreactor groove, and includes means interconnecting said blade legs, saidinterconnecting means being spaced from said reactor and being movablerelative to said reactor.

11. A ski binding according to claim 10 wherein said interconnectingmeans includes a bar, screw means extending between said bar and saidreactor, whereby adjustment of said screw means changes the spacingbetween said bar and said reactor, thereby changing the stresses inducedin said blade by said reactor and said interconnecting means.

12. A ski binding according to claim 8 including means for selectivelychanging the deflection of said blade against said base when a ski bootof predetermined dimensions is clamped by said clamping means, wherebythe amount of additional deflection of said blade necessary to causesnapping of said blade can be adjusted.

13. A ski binding according to claim 12 wherein said deflection changingmeans includes screw means between saidhousing and'said reaction means,said reaction means being displaced relative to said housing uponoperation of said screw means. 7

14. A ski binding according to claim 8 wherein said connecting meansincluding a tension link, means pivotally fastening one end of saidtension link to said base, the other end of said tension link beingpivotally fastened to said housing at said transverse axis, said tensionlink being inclined rearwardly when a boot is clamped in said clampingmeans, whereby said tension link draws said housing forwardly.

15. A ski binding according to claim 8 including means for adjustingsaid transverse axis forwardly and rearwardly relative to said housing,whereby the leverage of said clamping means and said reaction means isadjustable.

16. A ski binding according to claim 15 wherein said connecting meansincludes a tension link mounted at one end for swinging movementrelative to said base about an axis parallel to said transverse axis,the other end of said link being pivotally fastened to said housing atsaid transverse axis, said adjusting means including an arcuate guide onsaid housing, and means for selectively displacing said link other endalong said guide.

17. A ski binding according to claim 10 including a pair of arms on saidreactor, said arms projecting forwardly of said reactor groove and beingmounted on said housing for swinging movement about an axis parallel tosaid transverse axis, said arms axis being positioned relative to saidtransverse axis to swing said housing about said transverse axis in thedirection of rendering said engaging means ineffective upon snapping ofsaid blade.

18. A ski binding according to claim 10 wherein said interconnectingmeans includes a pair of arms, said arms being mounted on said housingfor swinging movement about an axis parallel to said transverse axis,said arms axis being positioned relative to said transverse axis toswing said housing about said transverse axis in the direction ofrendering said engaging means ineffective upon snapping of said blade.

19. A ski binding according to claim 10 wherein said interconnectingmeans includes a tension bar having a pair of 0pposed slots, oppositeends of said reactor being received in said bar slots, means restrictingrotation of said reactor relative to said tension bar, means securingsaid blade legs at opposite ends of said tension bar whereby saidtension bar slots allow adjustment of the spacing between said reactorand said tension bar.

20. In a ski binding having a base, lever means for engaging a portionof a ski boot, and means for resisting movement of said lever means in adirection which would allow release of said boot, said resisting meanscomprising a thin resilient element of sheet material including alongitudinally extending segment having a first end spaced from saidbase and a second end adjacent said base and front and back faces, saidsegment having a first stable three dimensional configuration in whichthe front face portion extending longitudinally from said first end isconcave in a transverse direction and in which the cross bucklingmodulus of successive transverse cross sections of said segmentdecreases monotonically from said first end, said lever being connectedwith said first end of said segment for moving said first end towardsaid base when said lever means is moving in said boot release directionand elastic buckling of successive transverse cross sections of saidsegment progresses longitudinally along said segment to said first endthereof and then said segment snaps over and assumes a second threedimensional configuration in which the front face portion extendinglongitudinally from said first end is convex, whereby said successiveelastic buckling of said segment progressively increases resistance tomovement of said lever in said release direction until said segmentsnaps over.

21. In a ski binding according to claim wherein said resisting meansincludes a reactor adjacent said first end, said segment having anarcuate edge along said first end, said reactor having an arcuate groovetherein, said segment edge being received in said reactor groove andhaving a greater radius of curvature than said reactor groove, saidsegment extending laterally at opposite ends of said edge, and means forapplying tension in said segment along said lateral portions, saidtension applying means acting in a direction urging said edge into saidgroove and thereby stressing said segment in compression adjacent saidgroove and in tension along said lateral portions.

22. In a ski binding according to claim 21 wherein said resisting meansincludes means for adjusting the deflection of said segment adjacentsaid second end due to elastic buckling of successive transverse crosssection, whereby additional deflection of said deflecting direction bysaid lever means necessary to cause snap over of said segment can beadjusted.

23. In a ski binding according to claim 21 wherein said tension applyingmeans includes a tension bar interconnecting said lateral portions,means for pivoting said tension bar about a transverse axis relative tosaid reactor, a prop, means pivotally mounting said prop on said tensionbar for swinging movement about an axis parallel to said tension barpivot axis, abutment means on said base for supporting said prop, andmeans for swinging said prop into engagement with said supporting meansupon rotation of said reactor about said pivot axis during snapover ofsaid segment, whereby said prop temporarily supports said tension bar tofacilitate snapping said segment back to said first three dimensionalconfiguration.

24. ln a ski binding according to claim 21, wherein said tensionapplying means includes a tension bar interconnecting said lateralportions, a prop, means mounting said prop on said segment adjacent saidfirst end, abutment means on said base for supporting said prop, andmeans for swinging said prop into engagement with said supporting meansupon snapping of said segment in said boot release direction, wherebysaid prop temporarily supports said reaction and segment to facilitatesnapping said segment back to said first three dimensionalconfiguration.

25. A ski binding comprising a base, a housing, said housing having atop and opposite side walls, tension link means connecting said housingwith said base for rotation about a transverse axis, a thin resilientsegment of sheet material having an inner end and an outer end, saidinner end including an arcuate edge, segment stressing means, saidstressing means including arms mounted on said side walls for pivotingsaid housing and stressing means relative to each other about atransverse axis spaced from said tension link axis, said stressing meansincluding a reactor having an arcuate groove with a smaller radius ofcurvature than said segment edge, said segment having lateral portionsat opposite ends of said arcuate edge, said stressing means alsoincluding a transverse tension bar secured between said lateral portionsat opposite ends of said arcuate edge, said segment being stressed bysaid tension bar and said reactor to assume a first three dimensionalstable configuration in which the front face portion extendinglongitudinally from said inner end is convex in a transverse direction,and in which the cross buckling modulus of successlve transverse crosssections of said segment decreases monotonically from said inner end.The back face of said segment being opposite said base, and means onsaid housing for engaging a portion of a ski boot and resisting forcesapplied in a direction away from said base.

26. A ski binding according to claim 25 wherein said housing side wallseach include an arcuate slot, a transverse shaft, said link meansincluding a tension link having bearing means for supporting saidtransverse shaft, said shaft extending through said slots in each sidewall, said tension link being pivotally mounted on said base forswinging movement about said transverse axis, and means on said housingfor selectively displacing said shaft along said slot.

27. The ski binding according to claim 26 including splines on saidshaft at opposite ends thereof, said slots each having gear teeth alongthe side opposite said base, said gear teeth being in position to engagesaid splines on said shaft, and including means for rotating said shaftrelative to said tension link, whereby said shaft is displacedprogressively along said arcuate slot.

28. A ski binding according to claim 27 wherein said rotating meansincludes a worm and a gear on said shaft in engagement with said worm,means on said housing holding said worm against axial movement, wherebyrotation of said worm rotates said gear and shaft for displacing saidshaft along said slot, the helix angle of said worm being sufiicientlygreat for friction locking said worm against rotation by said gear.

29. A ski binding according to claim 28 wherein said side walls eachinclude an arcuate step, said step in each side wall being aligned withsaid arcuate slot, thereby offsetting the side of said slot adjacentsaid base from said geared side, said splines terminating intermediatesaid offset side of said geared sid'e, whereby said splines engage onlysaid geared side.

30. A ski binding according to claim 26 wherein said tension linkincludes bearing means supporting a transverse bar, said base includinga bracket extending upwardly from said base, said bracket having a slottherein projecting forwardly and upwardly from said base, said bar beingreceived in said slot and being movable along said slot, a step leveradjacent said base, said step lever being hingedly mounted on said bar,whereby snapping of said segment displaces said bar along said slot,thereby lifting said lever relative to said base and said lever being inposition for cocking said unit when said lever is raised.

31. A ski binding according to claim 30 including means for temporarilysupporting said stressing means on said base when said segment issnapped over to said second configuration.

32. A ski binding according to claim 30 wherein said bracket includes aguide surface in position for engagement by the heel of a boot andpositioning said boot with respect to said base, said housing includinga heel clamp, said clamp having a shoulder positioned in opposition tosaid base when said segment is in said first configuration and means foradjusting said shoulder relative to said base.

33. A ski binding according to claim 32 wherein said heel clamp includescam surfaces at opposite ends of said shoulder, said cam surfaces beinginclined laterally, whereby the lateral force of a heel against said camis transmitted to said segment tending to snap over said segment fromsaid first configuration to said second configuration.

34. In a ski binding unit of the type having a boot supporting surface,means for dislodging ice and snow from said boot comprising a pluralityof corrugations on said support surface, said corrugations includinginclined side walls and peaks, said inclined side walls having a surfaceof a low coefficient of friction, said peaks having a surface of ahigher coefiicient of friction than said side walls whereby said peakswedge into accumulations of ice and snow of a boot when said boot isplaced on said surface.

1. A ski binding comprising: a base, clamping means on said base, saidclamping means including a transverse pivot shaft mounted on said baseand including lever means extending longitudinally of said base andpivotally supported on said shaft, spring means extending between saidlever means and said base, said clamping means including a boot clampingabutment, said abutment being on the opposite side of said transverseshaft from said spring means, said spring means yieldably resistingpivoting of said lever means about said shaft in a direction which movessaid clamping abutment away from said base, and release means mountedbetween said spring means and said lever means for removing theresistance of said spring means in response to pivoting of said levermeans about said shaft when said abutment means has moved apredetermined distance away from said base, said release means allowingsaid lever means to pivot about said shaft to move said abutment awayfrom said base a distance greater than said predetermined distancewithout interference by said spring means, whereby release of said skiboot occurs substantially instantaneously and without sudden variationsin spring resistance prior to release.
 2. The ski binding according toclaim 1 including a second transverse shaft on said base, link meansextending between said second shaft and said pivot shaft, and means fordisplacing said second shaft relative to said base upon movement of saidabutment beyond said predetermined distance, whereby said clampingabutment moves away from said base upon release.
 3. The ski bindingaccording to claim 1 wherein said lever means includes means foradjusting the distance separating said clamping abutment and said springmeans from said shaft, whereby the spring force transmitted by saidspring means to clamping abutment is adjustable.
 4. A ski bindingcomprising: a base, clamping means on said base, said clamping meansbeing movable a predetermined distance relative to said base from aposition for clamping a ski boot on said base to a position wherein aski boot would be released in response to a predetermined force appliedto said clamping means in a predetermined direction, said clamping meansincluding a clamping abutment and lever means movable with said abutmentabout a transverse axis relative to said base, spring means yieldablyresisting displacement oF said clamping means, said spring meansproviding progressively increasing resistance in response todisplacement of said clamping means in said direction until saidpredetermined force causes said clamping means to move to said releasedposition, said spring means including a blade having an inner end and anouter end, said blade outer end being in engagement with said base, saidblade inner end being connected with said lever means for deflectingsaid blade upon pivoting said lever means about said axis, said springmeans having a greater resistance to deflection adjacent said inner endthan adjacent said outer end, and means for adjusting the magnitude ofsaid predetermined distance substantially independently of saidpredetermined force, whereby said blade deflects progressively fromadjacent said outer end toward said inner end.
 5. The ski bindingaccording to claim 4 wherein said clamping means includes a transverseshaft supporting said lever means for pivoting movement about saidshaft.
 6. The ski binding according to claim 5 including a transversebar, means mounting said bar on said base, and means connecting saidshaft with said bar for swinging movement of said shaft along acylindrical path about said bar, whereby swinging said shaft along saidpath changes the leverage between said abutment and said blade, and saidbar retains said lever means in a predetermined position with respect tosaid base during movement of said shaft along said path.
 7. The skibinding according to claim 6 wherein said lever means includes a housinghaving a pair of side walls extending longitudinally of said levermeans, said side walls having arcuate slots therein, said shaftextending through said slots, and means for temporarily locking saidshaft against movement along said slots.
 8. A ski binding comprising abase, a housing, means connecting said housing with said base, saidconnecting means including means for pivoting said housing about atransverse axis relative to said base, means on said housing cooperatingwith said base for clamping a ski boot, reaction means, said reactionmeans including a blade of thin resiliently flexible sheet materialinterconnecting said housing and said base, said blade being stressed toseek to assume a substantially conical bistable configuration and beingcapable of snapping from a concave configuration on one face of saidblade to a concave configuration on the opposite face of said blade upona predetermined deflection of said blade against said base, saidtransverse axis being between said blade and said clamping means, saidclamping means being rendered ineffective upon snapping of said bladefrom one configuration to the other, whereby the application of a forceagainst said clamping means is transmitted through said housing to saidblade to deflect said blade against said base progressively andultimately to snap said blade when a predetermined force is applied tosaid clamping means.
 9. A ski binding according to claim 8 wherein saidblade has adjacent said housing a bearing edge located intermediate thelateral margins of said blade and having legs extending outwardlytherefrom at locations on opposite sides of said bearing edge, saidreaction means also including means for pressing against said bearingedge and for pulling on said legs to load said blade so that said sheetmaterial thereof adjacent said bearing edge is in compression and thesheet material thereof spaced from said edge is in tension, whereby saidblade is distorted elastically to seek alternately both of said concaveconfigurations.
 10. A ski binding according to claim 9 wherein saidpressing and pulling means includes a reactor, said reactor having anarcuate groove therein, said bearing edge being arcuate and having agreater radius of curvature than said reactor groove, said bearing edgebeing received in said reactor groove, and includes meansinterconnecting said blade legs, said interconnecting means being spacedfrom said reactor and being movAble relative to said reactor.
 11. A skibinding according to claim 10 wherein said interconnecting meansincludes a bar, screw means extending between said bar and said reactor,whereby adjustment of said screw means changes the spacing between saidbar and said reactor, thereby changing the stresses induced in saidblade by said reactor and said interconnecting means.
 12. A ski bindingaccording to claim 8 including means for selectively changing thedeflection of said blade against said base when a ski boot ofpredetermined dimensions is clamped by said clamping means, whereby theamount of additional deflection of said blade necessary to causesnapping of said blade can be adjusted.
 13. A ski binding according toclaim 12 wherein said deflection changing means includes screw meansbetween said housing and said reaction means, said reaction means beingdisplaced relative to said housing upon operation of said screw means.14. A ski binding according to claim 8 wherein said connecting meansincluding a tension link, means pivotally fastening one end of saidtension link to said base, the other end of said tension link beingpivotally fastened to said housing at said transverse axis, said tensionlink being inclined rearwardly when a boot is clamped in said clampingmeans, whereby said tension link draws said housing forwardly.
 15. A skibinding according to claim 8 including means for adjusting saidtransverse axis forwardly and rearwardly relative to said housing,whereby the leverage of said clamping means and said reaction means isadjustable.
 16. A ski binding according to claim 15 wherein saidconnecting means includes a tension link mounted at one end for swingingmovement relative to said base about an axis parallel to said transverseaxis, the other end of said link being pivotally fastened to saidhousing at said transverse axis, said adjusting means including anarcuate guide on said housing, and means for selectively displacing saidlink other end along said guide.
 17. A ski binding according to claim 10including a pair of arms on said reactor, said arms projecting forwardlyof said reactor groove and being mounted on said housing for swingingmovement about an axis parallel to said transverse axis, said arms axisbeing positioned relative to said transverse axis to swing said housingabout said transverse axis in the direction of rendering said engagingmeans ineffective upon snapping of said blade.
 18. A ski bindingaccording to claim 10 wherein said interconnecting means includes a pairof arms, said arms being mounted on said housing for swinging movementabout an axis parallel to said transverse axis, said arms axis beingpositioned relative to said transverse axis to swing said housing aboutsaid transverse axis in the direction of rendering said engaging meansineffective upon snapping of said blade.
 19. A ski binding according toclaim 10 wherein said interconnecting means includes a tension barhaving a pair of opposed slots, opposite ends of said reactor beingreceived in said bar slots, means restricting rotation of said reactorrelative to said tension bar, means securing said blade legs at oppositeends of said tension bar whereby said tension bar slots allow adjustmentof the spacing between said reactor and said tension bar.
 20. In a skibinding having a base, lever means for engaging a portion of a ski boot,and means for resisting movement of said lever means in a directionwhich would allow release of said boot, said resisting means comprisinga thin resilient element of sheet material including a longitudinallyextending segment having a first end spaced from said base and a secondend adjacent said base and front and back faces, said segment having afirst stable three dimensional configuration in which the front faceportion extending longitudinally from said first end is concave in atransverse direction and in which the cross buckling modulus ofsuccessive transverse cross sections of said segment decreasesmonotoniCally from said first end, said lever being connected with saidfirst end of said segment for moving said first end toward said basewhen said lever means is moving in said boot release direction andelastic buckling of successive transverse cross sections of said segmentprogresses longitudinally along said segment to said first end thereofand then said segment snaps over and assumes a second three dimensionalconfiguration in which the front face portion extending longitudinallyfrom said first end is convex, whereby said successive elastic bucklingof said segment progressively increases resistance to movement of saidlever in said release direction until said segment snaps over.
 21. In aski binding according to claim 20 wherein said resisting means includesa reactor adjacent said first end, said segment having an arcuate edgealong said first end, said reactor having an arcuate groove therein,said segment edge being received in said reactor groove and having agreater radius of curvature than said reactor groove, said segmentextending laterally at opposite ends of said edge, and means forapplying tension in said segment along said lateral portions, saidtension applying means acting in a direction urging said edge into saidgroove and thereby stressing said segment in compression adjacent saidgroove and in tension along said lateral portions.
 22. In a ski bindingaccording to claim 21 wherein said resisting means includes means foradjusting the deflection of said segment adjacent said second end due toelastic buckling of successive transverse cross section, wherebyadditional deflection of said deflecting direction by said lever meansnecessary to cause snap over of said segment can be adjusted.
 23. In aski binding according to claim 21 wherein said tension applying meansincludes a tension bar interconnecting said lateral portions, means forpivoting said tension bar about a transverse axis relative to saidreactor, a prop, means pivotally mounting said prop on said tension barfor swinging movement about an axis parallel to said tension bar pivotaxis, abutment means on said base for supporting said prop, and meansfor swinging said prop into engagement with said supporting means uponrotation of said reactor about said pivot axis during snapover of saidsegment, whereby said prop temporarily supports said tension bar tofacilitate snapping said segment back to said first three dimensionalconfiguration.
 24. In a ski binding according to claim 21, wherein saidtension applying means includes a tension bar interconnecting saidlateral portions, a prop, means mounting said prop on said segmentadjacent said first end, abutment means on said base for supporting saidprop, and means for swinging said prop into engagement with saidsupporting means upon snapping of said segment in said boot releasedirection, whereby said prop temporarily supports said reaction andsegment to facilitate snapping said segment back to said first threedimensional configuration.
 25. A ski binding comprising a base, ahousing, said housing having a top and opposite side walls, tension linkmeans connecting said housing with said base for rotation about atransverse axis, a thin resilient segment of sheet material having aninner end and an outer end, said inner end including an arcuate edge,segment stressing means, said stressing means including arms mounted onsaid side walls for pivoting said housing and stressing means relativeto each other about a transverse axis spaced from said tension linkaxis, said stressing means including a reactor having an arcuate groovewith a smaller radius of curvature than said segment edge, said segmenthaving lateral portions at opposite ends of said arcuate edge, saidstressing means also including a transverse tension bar secured betweensaid lateral portions at opposite ends of said arcuate edge, saidsegment being stressed by said tension bar and said reactor to assume afirst three dimensional stable configuration in which the Front faceportion extending longitudinally from said inner end is convex in atransverse direction, and in which the cross buckling modulus ofsuccessive transverse cross sections of said segment decreasesmonotonically from said inner end. The back face of said segment beingopposite said base, and means on said housing for engaging a portion ofa ski boot and resisting forces applied in a direction away from saidbase.
 26. A ski binding according to claim 25 wherein said housing sidewalls each include an arcuate slot, a transverse shaft, said link meansincluding a tension link having bearing means for supporting saidtransverse shaft, said shaft extending through said slots in each sidewall, said tension link being pivotally mounted on said base forswinging movement about said transverse axis, and means on said housingfor selectively displacing said shaft along said slot.
 27. The skibinding according to claim 26 including splines on said shaft atopposite ends thereof, said slots each having gear teeth along the sideopposite said base, said gear teeth being in position to engage saidsplines on said shaft, and including means for rotating said shaftrelative to said tension link, whereby said shaft is displacedprogressively along said arcuate slot.
 28. A ski binding according toclaim 27 wherein said rotating means includes a worm and a gear on saidshaft in engagement with said worm, means on said housing holding saidworm against axial movement, whereby rotation of said worm rotates saidgear and shaft for displacing said shaft along said slot, the helixangle of said worm being sufficiently great for friction locking saidworm against rotation by said gear.
 29. A ski binding according to claim28 wherein said side walls each include an arcuate step, said step ineach side wall being aligned with said arcuate slot, thereby offsettingthe side of said slot adjacent said base from said geared side, saidsplines terminating intermediate said offset side of said geared side,whereby said splines engage only said geared side.
 30. A ski bindingaccording to claim 26 wherein said tension link includes bearing meanssupporting a transverse bar, said base including a bracket extendingupwardly from said base, said bracket having a slot therein projectingforwardly and upwardly from said base, said bar being received in saidslot and being movable along said slot, a step lever adjacent said base,said step lever being hingedly mounted on said bar, whereby snapping ofsaid segment displaces said bar along said slot, thereby lifting saidlever relative to said base and said lever being in position for cockingsaid unit when said lever is raised.
 31. A ski binding according toclaim 30 including means for temporarily supporting said stressing meanson said base when said segment is snapped over to said secondconfiguration.
 32. A ski binding according to claim 30 wherein saidbracket includes a guide surface in position for engagement by the heelof a boot and positioning said boot with respect to said base, saidhousing including a heel clamp, said clamp having a shoulder positionedin opposition to said base when said segment is in said firstconfiguration and means for adjusting said shoulder relative to saidbase.
 33. A ski binding according to claim 32 wherein said heel clampincludes cam surfaces at opposite ends of said shoulder, said camsurfaces being inclined laterally, whereby the lateral force of a heelagainst said cam is transmitted to said segment tending to snap oversaid segment from said first configuration to said second configuration.34. In a ski binding unit of the type having a boot supporting surface,means for dislodging ice and snow from said boot comprising a pluralityof corrugations on said support surface, said corrugations includinginclined side walls and peaks, said inclined side walls having a surfaceof a low coefficient of friction, said peaks having a surface of ahigher coefficient of friction than said side Walls whereby said peakswedge into accumulations of ice and snow of a boot when said boot isplaced on said surface.